Lint filter bag



8- 1961 M. CORDELL 2,995,205

1.1m FILTER BAG Filed June 5. 1959 2 Sheets-Sheet 1 INVENTOR. M4877filefia zz ATTOIQ/VEY M. CORDELL LINT FILTER BAG Aug. 8, 1961 2Sheets-Sheet 2 Filed June 5. 1959 INVENTOR. Wei-0v (@Qfi'dl ATTOZ/VEYUnited States Patent 2,995,205 LINT FILTER BAG Martin Cordell, FarRockaway, N.Y., assignor to Studley Paper Company, Inc., a corporationof New York Filed June 5, 1959, Ser. No. 818,275 8 Claims. (Cl. 183-51)This invention relates generally to lint or similar filters andparticularly to an improved lint filter intended for use in connectionwith clothes drying equipment; the present invention also relating to anovel method of assembling such a filter.

The primary operation with which the invention is concerned is theremoval of lint from clothing and other fabrics or laundry items whichhave been inserted in conventional automatic dryers after washing andcleaning. Such dryers frequently accomplish their function by exposingtheir contents to the impingement of a stream of warm air which isthereafter permitted to emerge from the dryers by way of a suitableexhaust outlet. The warm air so emerging carries with it a quantity oflint, as well as other foreign particles, which have become detachedfrom the said clothing, fabrics, etc., during the drying operation.

By reason of the presence of these particles it has been found desirableto provide suitable filters for their accumulation and disposal.Conventional filters of this kind have, among other things, taken theform of paper bags which may be attached to an air exhaust outlet of aclothes dryer and removed when they have been filled with foreignmaterial. Such bags are frequently composed of a porous paper which ispervious to air but which retains the airborne particles within theconfines of the bags.

In making use of these bags, it has been found desirable to be able toobserve the quantity of foreign particles which has accumulated thereinand, accordingly, it has been found particularly advantageous toincorporate windows in such bags whereby observation of their contentsmay be had. The windows thus provided take the form of flexible,transparent plastic films disposed over suitable apertures in the sidesof the bags and secured by an adhesive, such as conventional glue, tothe surfaces surrounding the apertures.

Experimentation has shown however that such a construction isaccompanied by a number of problems which severely limit its utility.Thus, it has been found that if the plastic films are secured directlyto the bag, its paper will absorb the adhesive to such an extent thatthere is a substantial risk of accidental loss or removal of the plasticfilms. The porosity and fluid receptivity of the paper composing the bagand the poor absorptive powers of the plastic films would appear to beprimarily responsible for this phenomenon. The risk of accidental lossso produced, while present at ordinary room temperatures, becomesparticularly great when the adhesive employed is exposed to highertemperatures such as characterize the warm air emerging from dryingequipment. Thus, such higher temperatures tend, in many instances, tosoften the plastic films to a semi-fluid condition and thereby promotethe opportunity for their detachment from the paper of the bag.Moreover, such temperatures may result in impairment of the transparencyof the conventional plastic films and may also cause them to becomebrittle or break.

In addition to these considerations, it has been found that the foreignparticles introduced within conventional filter bags become lodgedbetween the plastic films and the paper to which they are secured. Hereagain, the aforesaid absorption of the adhesive magnifies this tendencysince the amount of space'which would otherwise be occupied by adhesivebecomes available for the reception of the said particles. .As a result,the filter bag be- Patented Aug. 8, 1961 ice comes difficult to cleanand the lodged particles tend to maintain the separation between theplastic film and adjacent paper, thereby increasing the likelihood ofaccidental loss of said film.

Accordingly, it is an object of the present invention to provide a lintfilter which has an eflicient window for permitting observation of itscontents.

Another object of the invention is to provide such a window which willbe resistant to the effects of the temperatures of warm air.

Another object of the invention is to provide an improved method forassembling such a window with a filter bag.

Another object of the invention is to provide a lint filter bag whichhas improved means for securing thereto a window permitting observationof its contents.

A further object of the invention is to provide a means for eliminatingthe tendency to accumulate foreign particles between the said window andthe adjacent portions of the filter bag.

A still further object of the invention is to provide a removable filterbag which is adapted to receive air at high tempertures and to retainforeign particles carried by said air and to separate the particles fromthe air in which they are entrained.

Yet a further object of the invention is to provide a lint filter ofsimple and economical design, which is adapted for mass production byconventional methods.

Other and more specific objects of the present invention will beapparent from the following description as read in connection with theaccompanying drawings.

The accompanying drawings illustrate one form of the invention. In thesedrawings:

FIGURE 1 is a perspective view showing this form of the invention inassociation with a portion of the warm air exhaust outlet of a clothesdryer;

FIGURES 2, 3 and 4 are, respectively, top, bottom and edge views of thesaid form of the invention wherein its various components are depictedin a substantially folded position;

FIGURE 5 is a cross-sectional view taken about the line 5-5 of FIGURE 2;

FIGURES 6 and 7 are perspective views wherein the components of the saidform of the invention are depicted in exploded form in various stages ofassembly;

, FIGURE 8 is a fragmentary cross-sectional view of an end portion ofthe said window; and

FIGURE 9 is an enlarged fragmentary cross-sectional view of a portion ofthe construction depicted in FIG- URE 5.

Referring primarily to FIGURE 1, the numeral 10 indicates a tubularexhaust outlet of a conventional laundry or clothes dryer. This outletis joined to the mouth of a sleeve, generally designated by the numeral11, by any suitable means such as a wire collar 12. As will behereinafter set forth in detail, the sleeve communicates with theinterior of a conventionally formed pleated, square-bottomed paper bag,generally designated by the numeral 13. This bag is constructed of amaterial pervious to air, such as a porous filter paper. As showninFIGURES 1 and 4, its mouth may be sealed by a double folded flap 14secured against opening by a pair of removable metal clips 15. 7

Important features of the invention reside in the construction of thesleeve and its mode of assembly with the bag. Thus, referring moreparticularly to FIGURE 7, the sleeve 11 includes a rectangular sheet 16composed of flexible transparent material, preferably Mylar plasticfilm. Mylar is a trade name for polyethylene terephthalate in sheetform. The said rectangular sheet is provided with .two longitudinalinfolded strips 17.

' *A second component of the sleeve consists of a rectangular sheet 18composed of paper have the same overall dimensions as that of theinfolded rectangular Mylar sheet 16. An elongated aperture 19 isprovided in the said sheet 18.

It is to be noted that the paper of which sheet 18 is composed is notcharacterized by the same absorbent powers which exist in the filterpaper of which bag 13 is formed. While the latter is characterized by apermeability by any fluid glue brought in contact therewith, sheet 18 iscomposed of paper which is less permeable and characterized by thewettability of its surface when exposed to a layer of fluid glue. Thesheet 18 is thus characterized by a substantial exclusion of said fluidglue from the interior of said paper upon the application thereof andduring drying of the glue, thereby avoiding rapid elimination of saidlayer of glue from the wetted surface and permitting said layer to formthereon in a solid substantially non-absorbed state. Thus, by reason ofthese characteristics, the paper of sheet 13 will maintain a substantiallayer of such adhesive between itself and any juxtaposed absorbentmaterial such as the paper of the bag, as well as any non-absorbentmaterial such as the Mylar plastic sheet 16. In so doing, a strong unionbetween said juxtaposed members is accomplished. One example of the kindof paper which may be used for sheet 18 is a smooth uncoated kraft paperbut other paper having the above-described characteristics of surfacewettability and exclusion of said adhesive during drying may also beused.

In assembling the sleeve, the transparent sheet 16 is first secured tothe paper sheet 18 by means of a suitable fluid adhesive interposedbetween the infolded strips 17 and the said paper sheet 18. One end ofthe sleeve is then double folded to the position generally designated bythe numeral 20 in FIGURE 7. This folded end may be sealed by theadhesive employed and also maintained in its folded position by suitableapplication of the adhesive between the lower fold of said end and theadjacent surface of the bag, as shown in FIGURE 8.

It is also noteworthy that in the sleeve thus formed the infolded strips17 of the transparent plastic sheet 16 overlap the longitudinal edges19a of the aperture 19, as indicated in FIGURE 7.

When the sleeve has been assembled as indicated above, it may bedisposed above the bag 13, as shown in FIG- URE 6, and then securedthereto in the position indicated in that figure by means of a suitablefluid adhesive inter posed between the paper sheet 18 and the bag 13,the adhesive being preferably applied to the paper sheet before bringingit into contact with the bag, thereby minimizing the opportunity forabsorption of the adhesive by the bag paper. During this operation, thebag 13 is preferably disposed in a folded position, as shown in FIGURE6. In securing sheet 18 to the bag, the mouth of the sleeve is leftfree, as may be seen in FIGURE 4. The double folded end portion of thesleeve may also advantageously be left free.

It is to be emphasized that the above described assembly is assured byreason of the presence of sheet 18 between the bag paper and Mylarsheet, which paper sheet, because of its previously notedcharacteristics, shields against the absorptive tendencies of the bagpaper and maintains an adhesive layer between itself and each of saidadjacent members disposed on opposing surfaces thereof. Thisconstruction thereby accomplishes a strong union of the variouscomponents of the assembly so as to minimize the risk of accidental lossor removal of said components and forms an effective seal to prevent theescape of the lint material.

The bag employed, as Well as the sleeve assembled therewith, may bestored or packaged in a flat folded condition, such as depicted inFIGURES 2, 3 and 4. The construction of this assembly may be betterappreciated by noting FIGURES and 9, which depict the overlapping backportions 21 of the bag, its pleated sides 22, the

paper sheet 18, transparent plastic sheet 16 and the layers of adhesive23, 24 securing said paper and Mylar sheets in assembled position.

The bag is provided with an elongated aperture 25, which is preferablyof the same conformation as that of the elongated aperture 19 of thepaper sheet. These apertures are aligned in juxtaposition when thedescribed form of the invention has been assembled.

Thus, the transparent plastic Mylar sheet when so assembled forms awindow whereby it is possible to observe the contents of the interior ofthe bag by viewing same through the transparent sheet 16 and theapertures 19, 25 covered thereby. The user is thus in a position todetermine whether the bag should be emptied or replaced.

With the foregoing construction, the free mouth of the sleeve may beeasily fastened to the tubular exhaust outlet 10, as depicted in FIGURE1, as by means of wire collar 12. When warm air emerges through the saidoutlet the sleeve and bag will expand, as shown in this figure. When thedouble folded end of the sleeve is left free, the expansion of the bagwill not tend to tear the seal thereof.

The warm air emerging from the tubular exhaust outlet will pass throughthe pervious filter paper of the bag. The temperatures of the said airwill not impair the Mylar sheet by reason of the ability of saidmaterial to resist softening and disintegration at high temperatures.The lint, as well as other foreign particles, carried by the airemerging from the outlet 10, is separated from the air stream andaccumulates in the bag where it may be observed through the aforesaidwindow.

It has been found in practice that any lint which may be disposed in thevicinity of the undersides of those portions 26 of the infolded stripswhich extend inwardly of apertures 19 and 25 will not tend to remainthereon or to accumulate between the infolded strips and paper sheet 18,and between the latter and the surface of bag 13, such tendency beingalso eliminated by the presence of the layers of edhesive maintainedbetween said portions of the invention. Thus, the lint and other foreignparticles will accumulate within the interior of the bag. When desired,the Wire collar 12 may be loosened, thereby permitting removal of thebag and disposition of its contents. The sleeve may then be refastenedto the exhaust outlet in the position described above, and the describedembodiment of the invention re-used as desired.

From'the foregoing, it will be seen that the invention accomplishes itsobjects in an ingenious yet simple manner and that the novel mode of itsassembly makes feasible the economic employment of the invention on awide scale.

The embodiment of the invention illustrated and described hereinabovehas been selected for the purpose of clearly setting forth theprinciples involved. It will be apparent, however, that the presentinvention is susceptible to being modified in respect to details ofconstruction, combination and arrangement of parts and materials whichmay be resorted to without departure from the spirit and scope of theinvention as claimed.

I claim:

1. An improved filter for removing lint or the like from air in which itis entrained comprising, in combination, a bag composed of a paperpervious to air but not lint and provided with an aperture in one sidethereof; means for introducing said air through said aperture; saidmeans including a transparent outer member and an intermediate membersecured by an adhesive between said outer member and said bag; the saidintermediate member being characterized by surfaces wettable uponcontact with said adhesive when the latter is in a fluid state, theinterior of said intermediate member also being characterized by asubstantial exclusion of said fluid adhesive during drying thereof ascompared with said air pervious paper, whereby a layer of said adhesivewill be retained upon the said surfaces.

2. An improved filter for removing lint from air comprising, incombination, a bag composed of a paper pervious to air and provided withan aperture in one side thereof; means for introducing said air throughsaid aperture; said means including an outer member composed of aflexible transparent plastic sheet and an intermediate paper sheetsecured by an adhesive between said outer member and said bag; the saidpaper sheet being characterized by surfaces wettable upon contact withsaid adhesive when the latter is in a fluid state, the interior of thesaid paper sheet also being characterized by a substantial exclusion ofsaid fluid adhesive during drying thereof, whereby a layer of saidadhesive will be retained upon the said surfaces.

3. An improved filter for removing lint from air comprising, incombination, a bag composed of a paper pervious to air and provided withan aperture in one side thereof; means for introducing said air throughsaid aperture; said means including an outer member composed of animpervious transparent film and an intermediate paper sheet secured byan adhesive between said outer member and said bag; the said paper sheetbeing characterized by surfaces wettable upon contact with said adhesivewhen the latter is in a fluid state, the interior of the said papersheet also being characterized by a substantial exclusion of said fluidadhesive during drying thereof, whereby a layer of said adhesive will beretained upon the said surfaces; the said paper sheet also beingprovided with an aperture aligned with the aperture of said bag, thesaid apertures defining means for communicating with the interior ofsaid bag,

4. An improved filter for removing lint from air comprising, incombination, a bag composed of a paper pervious to air and provided withan aperture in one side thereof; means for introducing said air throughsaid aperture; said means including an outer member composed of atransparent plastic sheet of Mylar and an intermediate paper sheetsecured by an adhesive between said outer member and said bag; the saidpaper sheet being characterized by surfaces wettable upon contact withsaid adhesive when the latter is in a fluid state, the interior of thesaid paper sheet also being characterized by a substantial exclusion ofsaid fluid adhesive during drying thereof, whereby a layer of saidadhesive will be retained upon the said surfaces; the said paper sheetalso being provided with an aperture aligned with the aperture of saidbag, the said apertures defining means for communicating with theinterior of said bag; the said outer member being provided with infoldedstrips overlapping and extending inwardly of the edges of saidapertures.

5. An improved filter for removing lint from air comprising, incombination, a bag composed of a paper pervious to air and provided withan aperture in one side thereof; means for introducing said air throughsaid aperture; said means including an outer member composed of atransparent plastic sheet and an intermediate paper sheet secured by anadhesive between said outer member and said bag; the said paper sheetbeing characterized by surfaces wettable upon contact with said adhesivewhen the latter is in a fluid state, the interior of the said papersheet also being characterized by a substantial exclusion of said fluidadhesive during drying thereof, whereby a layer of said adhesive will beretained upon the said surfaces; the said paper sheet also beingprovided with an aperture aligned with the aperture of said bag, thesaid apertures defining means for communicating with the interior ofsaid bag; the said outer member being provided with infolded stripsoverlapping and extending inwardly of the edges of said apertures; thesaid apertures also being defined by a layer of said adhesive disposedon each side of said paper sheet.

6. An improved filter for removing lint from air comprising, incombination, a bag composed of a paper pervious to air and provided withan elongated aperture in one side thereof; a rectangular sheet oftransparent Mylar disposed exteriorly of said bag and provided with apair of longitudinal infolded strips; a rectangular sheet of paperdisposed between said Mylar and said bag; the said sheet of paper beingprovided with an elongated aperture conforming with the elongatedaperture of said bag and aligned therewith; the said sheet of paperbeing secured to the said bag and infolded strips by an adhesive appliedin an initially liquid form to the margins of said elongated apertures;one end portion of said Mylar sheet being adhesively sealed and foldedwith one end portion of said sheet of paper; the opposite end portionsof said Mylar sheet and sheet of paper being left unsealed; the saidpaper sheet also being provided with an aperture aligned with theaperture of said bag; the said Mylar sheet and sheet of paper defining asleeve communicating with the interior of said bag; the said paper sheetbeing characterized by surfaces wettable upon contact with said adhesivewhen the latter is in a fluid state, the interior of the said papersheet also being characterized by a substantial exclusion of said fluidadhesive during drying thereof, whereby a layer of said adhesive will beretained upon the said surfaces.

7. An improved method of constructing a filter for removing lint fromair comprising, in combination, the step of applying a fluid adhesive tothe margin of an aperture formed in a sheet of paper characterized bysurfaces wettable upon contact with said adhesive, the interior of saidpaper also being characterized by a substantial exclusion of said fluidadhesive during drying thereof, whereby a layer of said adhesive will beretained upon the said surfaces; the step of securing said sheet ofpaper upon a bag composed of paper pervious to air, the said bag beingprovided with an aperture aligned with the aperture of said sheet ofpaper; the step of securing a transparent plastic sheet to said papersheet, the said paper sheet being provided with said adhesive on bothsides thereof; the said plastic sheet being provided with a pair ofinfolded longitudinal strips contactable with said adhesive on saidsheet of paper; and the step of folding and adhesively securing one endof said plastic sheet together with the adjacent end of said papersheet, whereby a seal of said end portions is effected.

8. The method according to claim 7, wherein said transparent plasticsheet comprises Mylar.

References Cited in the file of this patent UNITED STATES PATENTS1,835,770 Gasner et al. Dec. 8, 1931 1,849,065 Biederman Mar. 15, 19322,227,212 Beck Dec. 31, 1940 2,577,863 Sosnowich Dec. 11, 1951 FOREIGNPATENTS 438,829 Germany Dec. 24, 1926 215,447 Australia Nov. 22, 1956

